B.7D Genetic Engineering Level 6.7 – 02

Have you heard the words genetic engineering, or GMO? Do you know what they mean and the research that is going on in this field.? Why are scientists so interested in these techniques? Are they helpful or harmful?

Genetic engineering is not a natural process. In this process, the genes of living things are changed by scientists. This alters their DNA. In these techniques segments of DNA can be added or deleted. Genes could also be added from one species to another. Genetically modified organisms (or GMO) are those that have been changed through gene alteration.

Selective breeding and cross breeding have been used for a long time to produce helpful traits. In this method plants and animals with certain traits are chosen for breeding. In time, this leads to offspring with those characteristics. However, this method can also pass on unwanted features. It also takes a long time.

There are a few basic steps when this method is used to modify genes. First the gene is identified. It is then separated from the donor organism. In the next step the fragment of DNA is inserted into a carrier like the plasmid of a bacterium. The final step is to grow this recombinant bacterium in a host.

In medicine this process has been used to make insulin. Insulin is a hormone that helps control the level of sugar in the blood. People with certain form of diabetes need to inject insulin. Where does this injectable insulin come from? Before genetic engineering, animal insulin was extracted from the pancreas of cows and pigs. Now with the help of genetic engineering, pure human insulin can be made. A plasmid (extra DNA) from bacterial cell is removed. Enzymes are used to cut a small piece of the plasmid. The gene for human insulin is then put into the gap. The modified plasmid is introduced back into a host bacterium. This cell produces insulin as it divides. This insulin is then filtered, purified, and given to people with diabetes.